BOGOTA — Colombia's President Juan Manuel Santos ordered an investigation into the apparent spying of his negotiating team at peace talks with Marxist FARC rebels and suggested that "dark forces" were trying to sabotage his bid to end five decades of war.

Military intelligence operatives intercepted cellular phone communications of the government's representatives at talks with the FARC, or Revolutionary Armed Forces of Colombia, weekly news magazine Semana reported on Tuesday.

Peace negotiations with the FARC began in November 2012, weeks after Santos announced he had been holding secret discussions with rebel leaders. News of the talks was leaked prior to Santos' historic announcement.

"It's not acceptable from any point of view that intelligence is conducted against ordinary citizens and much less against state officials," said Santos, calling those behind the spying "dark forces" and "loose wheels." "It's totally unacceptable."

The peace negotiations — underway in Cuba - have surfaced as a campaign issue ahead of elections in May in which Santos is running for reelection. Semana, a prestigious investigative magazine, said the cellular phones of negotiators Humberto de la Calle, Sergio Jaramillo and Alejandro Eder were intercepted, as well as leftist politicians, like former Senator Piedad Cordoba.

Data from text messages were collected, but telephone calls were not listened to, it reported. The espionage was conducted from a Bogota restaurant and adjoining Internet center set up as front for the operation.

This is the first spy scandal to emerge since the government intelligence agency known as the DAS was shut down after revelations of wire-tapping during the government of former President Alvaro Uribe.

"My hand hasn't wavered in the fight against the illegal use of intelligence," said Santos, who as Uribe's defense minister called for the spy agency to be shuttered.

The government and FARC have fought for five decades leaving more than 200,000 dead and millions displaced. The peace talks, while mostly popular, have some detractors, like Uribe and his party's choice as candidate for president in May, Oscar Ivan Zuluaga.

Uribe denied any involvement in the spying and called any media suggestion that he was behind it, an "infamy" and "smoke screen."

The aim of the intelligence operation, code named "Andromeda," was to garner as much information as possible about what was being discussed at the talks in Havana, according to a source cited by Semana.

Commenting on the report, Interior Minister Aurelio Iragorri said, "The most important is to carry out an internal investigation because this government at no time — no minister or the president — has given any instructions to interfere with communications of anyone." "In this case we are more the victims than the victimizer," he added.

Colombia's President Juan Manuel Santos ordered an investigation into the apparent spying of his negotiating team at peace talks with Marxist FARC rebels and suggested that "dark forces" were trying to sabotage his bid to end five decades of war.